BOUNDARY INTEGRAL METHODS FOR THE POISSON EQUATION OF CONTINUUM DIELECTRIC SOLVATION MODELS

This article tests a dielectric model for the variation of hydration f ree energy with the geometry of complex solutes in water. It reexpress es the Poisson equation of the model to examine the basic aspects of b oundary integral methods for these problems. It compares eight example s of dielectric model potentials of mean force in water with numerical results obtained from molecular scale models by simulation. Instructi ve and physical results are obtained but the model overstabilizes attr active, ion-pairing configurations. The article describes the algorith ms, alternative to those in the literature, used here for high-precisi on solutions of that Poisson equation. Anticipating multigrid boundary integral approaches for similarly accurate treatment of larger soluti on complexes, the adaptation of spatial resolution is discussed. Final ly, the statistical mechanical theory of the model is discussed togeth er with a new proposal for describing the molecular detail of the solv ation properties: integrating-out a probe solvent molecule using the d ielectric model. The appendices give formal results relevant to period ic boundary conditions and infinite area surfaces such as solution int erfaces and membranes. (C) 1997 John Wiley & Sons, Inc.